RESUMO
Purpose To investigate the effects of hypoxia inducible factor-2α (HIF-2ot) siRNA on proliferation and chemotherapy sensitivity of breast carcinoma MCF-7.Methods RNA interference was used to silence the expression of HIF-2α in MCF-7 cells.The changes of HIF-2α gene expression were detected by immunocytochemistry and RT-PCR.Under hypoxia environment simulated by CoCl2,MTT assay and flow cytometry (FCM) were used to measure cell growth inhibition rate and cell apoptosis of MCF-7 cells under different dosages of chemotherapeutic agents (5-fluorouracil,adriamycin,and paclitaxel).Results Expression of HIF-2α in MCF-7 were down-regulated by HIF-2α siRNA (P ＜ 0.05).The proliferation inhibition and apoptosis rates were evidently increased after transfection with HIF-2α siRNA (P ＜ 0.05),chemotherapy drug sensitivity was enhanced.Conclusion HIF-2α siRNA can induce the apoptosis and inhibit the proliferation and enhance the sensitivity of breast carcinoma MCF-7 cell line to chemotherapeutic agents.Blocking HIF-2α maybe a very promising strategy for breast carcinoma gene therapy in combination with chemotherapy.